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1、农业环境科学学报2009,28(1):107-111JournalofAgro-EnvironmentScience低山丘陵区红壤酸雨中典型阴离子垂直迁移状况及模拟1112111方堃,陈效民,杜臻杰,张佳宝,邓建强,孙江慧,周春明(1.南京农业大学资源与环境科学学院,江苏南京210095;2.中国科学院南京土壤研究所,江苏南京210008)摘要:酸雨中的SO2--2--4和NO3等阴离子在土壤中迁移时会引起大量的盐基离子淋溶,导致土壤退化。用室内土柱模拟SO4和NO3在红壤旱地各土层中的垂直穿透状况,
2、并用Hydrus-1D模型对试验结果进行了拟合和预测。结果表明,NO-3在红壤各层中的穿透速度较快,其中在耕作层的穿透曲线峰值最高,C/C2-0达到0.39,峰值高低顺序依次为:耕作层>母质层>淋溶层>犁底层。SO4在土柱中的穿透速度远低于NO-3,穿透曲线有明显的拖尾现象。其在各土层的穿透时间依次为:母质层>犁底层>淋溶层>耕作层;而其峰值高低顺序依次为:耕作层>淋溶层>母质层>犁底层,最高点耕作层的顶点C/C0仅为0.22。用Hydrus-1D模型对试验结果进行模拟,所得的SO2--4和NO3穿透
3、土壤的浓度模拟值与其实测值均呈极显著的正相关关系。利用数学模拟获得了饱和导水率和垂直扩散率等溶质运移参数,并预测了研究区酸雨后SO2--2-4和NO3在红壤耕层的迁移状况,表明SO4会在酸雨结束后持续淋溶,从而影响土壤中Ca、Mg等盐基离子的淋失。关键词:红壤;酸雨阴离子;穿透曲线;Hydrus-1D模型中图分类号:S153.2文献标志码:A文章编号:1672-2043(2009)01-0107-052--SO4andNO3BreakThroughSituationsinRepresentativeR
4、edSoilsandPredictionbyHydrus-1DModelFANGKun1,CHENXiao-min1,DUZhen-jie1,ZHANGJia-bao2,DENGJian-qiang1,SUNJiang-hui1,ZHOUChun-ming1(1.CollegeofResourcesandEnvironmentalSciences,NanjingAgriculturalUniversity,Nanjing210095,China;2.InstituieofSoilScience,Chi
5、neseAcademyofSciences,Nanjing210008,China)Abstract:Acidrainisaglobalmenacefromagricultural,environmentalandecologicalperspective.SO2--4andNO3aremajoranionsinacidrainwhichcanspeedupsoilacidificationandresultinleachinglossesofthebasiccations.Inthisstudy,s
6、omesoilcolumnswereusedtode-scribethebreakthroughcurves(BTCs)ofinfiltrationofSO2--2-4andNO3intypicalredsoils.ThebreakthroughvelocityofSO4waslowerthanthatofNO--3.AremarkabledifferenceinBTCsofNO3wasobservedindifferentsoillayers.ThepeakvalueofBTCsinploughla
7、yer,havingC/C0value0.39,wasthehighestinsoilprofiles.OrderofthepeakvalueofBTCswasploughlayer>parentmateriallayer>leachedlayer>plowpanlayer.TrackofBTCsofSO2-4wasprolongedobviouslyineachlayer.ThepeakvalueofBTCs(0.22)inploughlayerwashigherthanotherlayers.Hy
8、drus-1Dmodelwasusedtosimulatethepenetrativeprocess.CorrelativecoefficientsofBTCsanditssimulationvaluewerehigherthan0.9.So,Hydrus-1DmodelprovedtobeausefultooltoestimatethepenetrativeprocessofSO2--4andNO3inredsoilregion.Theinfiltra